Review and Measurements of Okto DAC8 8Ch DAC & Amp

[Zooqu1ko]

Order #207, placed 2020-09-03 is scheduled to be shipped late next week.

Does the firmware that is currently shipping work with Linux?

 

[wineds]

Order #207, placed 2020-09-03 is scheduled to be shipped late next week.

Does the firmware that is currently shipping work with Linux?

Yes I am using DietPi so it should work with other Linux distros too.

 

[mkt]

Order #207, placed 2020-09-03 is scheduled to be shipped late next week.

Does the firmware that is currently shipping work with Linux?

Order #191 placed 2020-08-03 and no news.

 

[Honken]

No news here either, #187 placed on 2020-07-29.

 

[SimonSambuca]

Hello to all

order #254 placed on 2020-11-18.... Oh that will be a long wait

 

[Zooqu1ko]

No news here either, #187 placed on 2020-07-29.

I've asked them by mail, I've got no idea how long before the actual shipping date of the DAC one would usually receive a notice from Okto.

 

[mkt]

Order #191 placed 2020-08-03 and no news.

Update: Pavel says 2 weeks

 

[Honken]

I've asked them by mail, I've got no idea how long before the actual shipping date of the DAC one would usually receive a notice from Okto.

Yeah, I don't really mind the long delivery time to be honest but I do mind the lack of communication and the misleading delivery time estimate*. That #191 is due for delivery soon gives me some hope for a delivery this year though, it'd make a nice christmas present for myself.

@Okto Research I really do wish you the best, but I do think you could gain some good will from being more transparent with your customers with regards to purchase lead times and firmware updates. I'm assuming good faith here and I'm guessing you're working your asses off trying to balance R&D with fulfilling orders and other day to day business, but I'm sure a lot of customers would appreciate more info.

*If I recall correctly, they estimated 10 weeks when I ordered mine, we're looking at double that now.

 

[SimonSambuca]

Hello,
is here anyone who runs the DAC together with a Minidsp nanoDIGI 2x8? I'm just wondering what kind of cable is the best to connect the devices together?
Greetings

 

[Vincentponcet]

Hello,
is here anyone who runs the DAC together with a Minidsp nanoDIGI 2x8? I'm just wondering what kind of cable is the best to connect the devices together?
Greetings

with spdif to AES cable.

Another solution, someone made a custom firmware which runs in the XMOS of DAC8PRO to perform the active crossover function.
https://github.com/fabriceo/AVDSP

 

[SimonSambuca]

Hello,
thank you very much for the answer. There are different SPDIF on AES cable. Some have 75 ohms and others 110 ohms and there are also very expensive versions that convert from 75 to 110 ohms. Probably the expensive cables with a conversion are necessary?

@Octo Research
Maybe you could give some tips here?

 

[Zooqu1ko]

Probably the expensive cables with a conversion are necessary?

I believe that was discussed in this thread before. Essentially you can get away with anything for short runs (~1m or so, I have no problems with ~3m at 48kHz). Otherwise look if you can find a second hand Canare BPJ-XP-TRA or Neutrik NADIT... somewhere.

 

[waynel]

Hello,
thank you very much for the answer. There are different SPDIF on AES cable. Some have 75 ohms and others 110 ohms and there are also very expensive versions that convert from 75 to 110 ohms. Probably the expensive cables with a conversion are necessary?

@Octo Research
Maybe you could give some tips here?

For short lengths the following will work fine
https://www.proaudiola.com/mobile/Product.aspx?id=6989


https://www.sweetwater.com/store/detail/DBoxCab1.5--pro-co-1.5-foot-d-box-digital-input-cable?mrkgadid=3274408718&mrkgcl=28&mrkgen=gpla&mrkgbflag=0&mrkgcat=accessories&acctid=21700000001645388&dskeywordid=92700046938453232&lid=92700046938453232&ds_s_kwgid=58700005283136159&ds_s_inventory_feed_id=97700000007215323&dsproductgroupid=603597271392&product_id=DBoxCab1.5&prodctry=US&prodlang=en&channel=online&storeid=&device=m&network=g&matchtype=&locationid=1013581&creative=249895767051&targetid=aud-945936780674la-603597271392&campaignid=1055581119&gclid=CjwKCAiA5IL-BRAzEiwA0lcWYvDyrASwVHfxoVRzy8oY2-pjB_5U6ZTxiM0uTo_uUEBCkNnwVaQmDRoCIbsQAvD_BwE&gclsrc=aw.ds

If the length is more than a few meters then a 240 ohm resistor should be soldered inside the xlr shell across signal and ground.

75 ohm cable is my preference because it’s easier to use resistors for matching and hide them in the xlr shell.

no need for transformers or even resistors if the cable is only a few meters. Btw Okto has also given this guidance .

see: https://www.audiosciencereview.com/...kto-dac8-8ch-dac-amp.7064/page-37#post-223984

That would certainly work, but is too complicated. AES inputs in the DAC8 PRO are terminated with 110Ohms as required by the standard, while the SPDIF expects 75Ohms. So a 220-240Ohm additional termination resistor will do the justice, since the digital receivers in the DAC8 PRO handle both SPDIF and AES voltage levels. But in fact, no resistor is needed at all if the cables are not very long. So a simple XLR M/RCA F adapter might work just fine in that case.

Pavel, Okto Research

Wayne

 

[John1959]

Hello,
is here anyone who runs the DAC together with a Minidsp nanoDIGI 2x8? I'm just wondering what kind of cable is the best to connect the devices together?
Greetings

Yes, as already mentioned just a AES/EBU male to S/PDIF). I would look at the PRO (web)shops. Prices depend mainly on the quality of the connectors but should not exceed US$10 to US$20 for a good quality 1,5 meter cable. Shorter ones are sometimes harder to find. I use something like these at €12 (1,5 meter 110 ohm). BTW, Okto Research warns in the owner's manual not to use a balanced to unbalanced cable, but that's only relevant for the analogue output (DAC to amp). This can be confusing.

 

[howard416]

Has anyone used this connected with a PC over USB with a software DSP (4/6/8 channel output)?

 

[Honken]

No news here either, #187 placed on 2020-07-29.

Update, it just arrived here. Definitely made my day!

 

[DrCWO]

Hi *,
I hope someone operating the dac8 pro with usb and Linux is willing to answer my questions:
- Can DAC volume be controlled via ALSA amixer?
- Or even better: When running the dac on a raspberry with roon can volume be controlled via roon or have I to use the DSP volume instead?
- If it can be controlled does the volume you set in roon show up on the display of the DAC meaning is it in sync with the roon setting?
- Can someone please post the output of „amixer contents“.

Thanks a lot

 

[DrCWO]

Hi,

DrCWO here is the amixer output you requested, this is for DAC8PRO firmware version 1.4 connected to a raspberry pi 4b on raspbian buster:

pi@raspberrypi:~ $ amixer -c 2 contents
numid=8,iface=CARD,name='Keep Interface'
; type=BOOLEAN,access=rw------,values=1
: values=off
numid=7,iface=CARD,name='OKTO RESEARCH Internal Clock Validity'
; type=BOOLEAN,access=r-------,values=1
: values=on
numid=3,iface=MIXER,name='DAC8PRO Playback Switch'
; type=BOOLEAN,access=rw------,values=8
: values=on,on,on,on,on,on,on,on
numid=4,iface=MIXER,name='DAC8PRO Playback Switch',index=1
; type=BOOLEAN,access=rw------,values=1
: values=on
numid=5,iface=MIXER,name='DAC8PRO Playback Volume'
; type=INTEGER,access=rw---R--,values=8,min=0,max=99,step=0
: values=99,99,99,99,99,99,99,99
| dBminmax-min=-99.00dB,max=0.00dB
numid=6,iface=MIXER,name='DAC8PRO Playback Volume',index=1
; type=INTEGER,access=rw---R--,values=1,min=0,max=99,step=0
: values=99
| dBminmax-min=-99.00dB,max=0.00dB
numid=2,iface=PCM,name='Capture Channel Map'
; type=INTEGER,access=r----R--,values=8,min=0,max=36,step=0
: values=0,0,0,0,0,0,0,0
| container
| chmap-fixed=FL,FR,FC,LFE,RL,RR,FLC,FRC

numid=1,iface=PCM,name='Playback Channel Map'
; type=INTEGER,access=r----R--,values=8,min=0,max=36,step=0
: values=3,4,7,8,5,6,12,13
| container
| chmap-fixed=FL,FR,FC,LFE,RL,RR,FLC,FRC


The play back volume value can be changed via amixer command but this does not match or affect the DAC8PRO volume setting. Not sure this is normal ? I have not used amixer volume control before and am not very familiar with ALSA, is the amixer volume control separate from the USB DAC volume control setting ?

Volume control via usb would be very convenient.

Hi, and thanks for the reply. I did not see it so I posted the Question again, sorry.
All I know in general the amixer volume directly affects the volume of the DAC chip. Guess this is implemented here the same way.
It seems there are two volume settings, one separate for each channel and another one with only one value, maybee this affects all?
With the command amixer -c 2 numid=5 aa,bb,cc,dd,ee,ff,gg,hh you should be able to set the volume of the individual channels aa to hh.
If I am right with amixer -c 2 numid=6 xx you should be able to set the volume off all channels. Would be great if you might figure this out for me.
I would expect that changing the overall volume should also change the value displayed by the DAC‘s frontpannel. But maybee Octo did not implement this yet in its firmware...

 

[Honken]

Can't help you with Roon as I don't use that. As for ALSA, that command does not change the Volume of the DAC itself, but setting all channels in one command works:

 $ amixer contents
...
numid=5,iface=MIXER,name='DAC8PRO  Playback Volume'
  ; type=INTEGER,access=rw---R--,values=8,min=0,max=99,step=0
  : values=99,99,99,99,99,99,99,99
  | dBminmax-min=-99.00dB,max=0.00dB
numid=6,iface=MIXER,name='DAC8PRO  Playback Volume',index=1
  ; type=INTEGER,access=rw---R--,values=1,min=0,max=99,step=0
  : values=99
  | dBminmax-min=-99.00dB,max=0.00dB
...
$ amixer cset numid=5 59
numid=5,iface=MIXER,name='DAC8PRO  Playback Volume'
  ; type=INTEGER,access=rw---R--,values=8,min=0,max=99,step=0
  : values=59,59,59,59,59,59,59,59
  | dBminmax-min=-99.00dB,max=0.00dB

Personally, I'm not too bothered as changing the volume with the remote is very convenient and the volume display is very legible even at longer distances.

I am hearing some hiss from the tweeter using the DAC8, something I didn't hear from the Topping D70 which I used before. It's very faint though, I need to bring my ear within 20cm or so to hear it. I think that the font used for displaying playback info could be made a bit bigger as I can't see it from my listening position - but the font stating the current input is very large. Changing the order or these two display fields would be nice, as changing inputs is something I assume quite a few won't do too often and then it'd be a conscious decision to do so.

Something that could be nicer but doesn't matter much is the volume/control wheel. It looks good but it only feels OK to operate. I don't care much as the Apple remote is very easy to use and the menus are intuitive.

But overall, I'm very happy with it - it delivers exactly what I hoped for (which is multiple, individually addressable outputs). The display is quite nice in person and if I power it with my power amplifiers powered on I only hear a very, very faint click sound from my speakers (the Topping D70 made a very loud 'thonk' sound when powering on).

I haven't tried the headphone amp but I assume it would work fine with my HD600s. Something I haven't investigated yet is if the headphone out is the output with index number 6 in the amixer output above. If it is that would be very nice as that'd allow for separate EQ and volume control from the speakers.

Edit: @Zooqu1ko In case it wasn't obvious from the message above, yes the current FW works with Linux. Running ALARM on a RPI4 here.

 

[DrCWO]

Thank's for the reply.
If I got you right you can change perceived volume via ALSA but the display of the DAC doesn't reflect this change right?
I wonder about the hiss! The DAC is the best ever measured here (1) Okto dac8 stereo DAC Review | Audio Science Review (ASR) Forum. Probably the output voltage of the DAC is too high for your amplifier. Can you go up with volume to 0dB without clipping the amp? If not you should get an XLR attenuator like that Amazon.com: Hosa XLR weiblich auf XLR männlich Eingangsdämpfungsregler: Electronics between the DAC and the Amp. This will decrease the hiss and increase the resolution of the DAC.